In underwater installations as for example in association with offshore oil activity, the interconnection between cables or between cables and equipment modules, for example located at the sea bottom, presents serious problems. A specific type of inductive connector is described in Norwegian Patent Application No. 84.0087. The present invention takes as a basis a situation corresponding to that in such previous disclosure, but as will appear from the following, the present invention has also in part more general uses.
Corrosion and pitting of materials included in the structure of such connectors or the like constitute one of the greatest problems in underwater installations in sea water and also frequently at other forms of electrical installations in which it cannot always be guaranteed that corrosion protection and encapsulation will prevent penetration of for example water or moisture. In particular when there is ambient sea water it is to be noted that the voltage level in a part of the electrical installation has much significance to the corrosion rate. When the voltages exceed about 1 volt, the corrosion will take place much more quickly than at lower voltages. This recognition constitutes some of the background for the solutions set forth in the following.
When transmitting and distributing electrical energy and signals respectively through cables and wires there will normally be employed much higher voltage levels than 1 volt, depending upon the transmission distances concerned. This also applies to a high degree in underwater installations in offshore oil activity.